Anti-corrosive pigmentary composition for coatings

ABSTRACT

PCT No. PCT/FR91/00299 Sec. 371 Date Dec. 14, 1992 Sec. 102(e) Date Dec. 14, 1992 PCT Filed Apr. 11, 1991 PCT Pub. No. WO91/16381 PCT Pub. Date Oct. 31, 1991.The invention concerns an anti-corrosive pigmentary composition characterized in that contains zinc 8-hydroxy-quinolate.

DESCRIPTIVE SUMMARY

The invention concerns an anti-corrosive pigmentary composition for coating characterized in that it contains zinc 8 -hydroxy-quinolate.

According to a preferred embodiment, the composition according to the invention is made of a pigment pulverulent mixture including, in combination, the percentage being expressed in relation to the total weight of the pigment mixture;

a) 0.5%-99.5% in weight of zinc 8-hydroxyquinolate,

b) 0.5%-99.5% in weight of at least one of the following compounds: zinc phosphate, iron phosphate, chromium phosphate, manganese phosphate, aluminum phosphate, aluminum oxide, calcium ferrite, zinc ferrite, magnesium ferrite, barium ferrite, iron ferrite, calcium borosilicate, barium borosilicate, calcium phosphosilicate, barium phosphosilicate, the complement consisting in pigment known in that type of application.

Application to anti-corrosive coatings, in particular for shipbuilding and protection of metal industrial works.

The present invention concerns an anti-corrosive pigmentary composition for painting coatings.

The invention applies more particularly to anti-corrosive coatings in particular for shipbuilding and protection of metal industrial works.

Paintings are the most usual means of protection against the risk of corrosion. They are generally pigment mixtures insoluble in suspension in a liquid medium, generally organic, and polymeric binders. After application on the substrate to be covered, the mixture hardens and leaves a solid film, adhering to the surface to be protected.

The most efficient pigments and the most often used on metal substrates are minimum and zinc chromate.

However, the legistlation recently brought into force in several European countries and the world over, have constrained the painting and varnish industry to replace the traditional anti-corrosive pigments , generally toxic, by products less dangerous for health and environment.

Thus anti-corrosive paintings containing more than 1% of strontium or zinc chromate must have a label indicating the risk of cancer in connection with their use.

The compositions containing heavy metals such as lead compounds, in particular minimum, are also subjected to a dissuasive legislation regarding their use.

The harmful effects of this toxicity on the environment and the expenses necessary for the protection of people in contact with these products are very important.

Much research has been carried out, in order to discover anti-corrosive pigments at the same time as efficient and as universally used as the strontium or zinc chromates, but less toxic for man and less harmful for the environment.

The use of zinc phosphates was initially proposed. It is usually admitted, and it has been shown by experience that, in spite of its interesting properties, this product is not in itself sufficient enough to achieve anti-corrosive performance at the level of that obtained with zinc chromates.

On contrary, presently, in commerce, there is a multiplication of pigmentary compositions containing zinc phosphates said to be "activated" by various organic substances or by various metal salts such as compounds with an aluminum, molybdenum, calcium base.

Unfortunately, the results achieved with anti-corrosive paintings containing the previously mentioned pigments are often disappointing as they are not long-lasting, due to the fast exhaustion of the activating agents by dissolution or decomposition.

Moreover, if some compositions are sometimes efficient in a given family of polymeric binders, this efficiency is generally lost when they are introduced in another family of polymeric binders.

In addition, many pigmentary compositions of this type often lead to a bad storage stability of the corresponding painting, by increase of viscosity and feeding-up.

The purpose of the invention is to offer anti-corrosive pigmentary compositions allowing to compensate for the above mentioned disadvantages, and particularly, presenting the following properties:

efficiency against corrosion higher or equal to that of zinc chromates, equal volume concentration, and for a similar binder,

absence of toxicity and suppression of the nuisances to the environment,

universal use in painting formulations in aqueous or organic medium, containing for example acrylic, vinyl binders, alkyde resins, epoxy resins, polyurethanes, chlorinated rubber,

stability during long-term storage of the realized formulations

The anti-corrosive pigmentary compositions according to the invention contain zinc 8-hydroxyquinolate as an agent of synergy against corrosion.

According to a preferred embodiment, at least one of the following pigments zinc phosphate, iron phosphate, chromium phosphate, manganese phosphate, aluminum phosphate, aluminum oxide, calcium ferrite, zinc ferrite, magnesium ferrite, barium ferrite, iron ferrite, calcium borosilicate, barium borosilicate, calcium phosphosilicate, barium phosphosilicate is associated to the zinc 8-hydroxyquinolate.

Preferably, the compositions according to the invention consist in a pigment pulverulent mixture including, in combination, the percentage being expressed in comparison with the total weight of the pigment mixture:

a) 0.5-99.5% by weight of zinc 8-hydroxyquinolate,

b) 0.5-99.5% by weight of at least one of the following pigments: zinc phosphate, iron phosphate, chromium phosphate, manganese phosphate, aluminum phosphate, aluminum oxide, calcium ferrite, zinc ferrite, magnesium ferrite, barium ferrite, iron ferrite, calcium borosilicate, barium bonosilicate, calcium phosphosilicate, barium phosphosilicate. The complement is made of the pigments known in that type of application.

Preferably, the percentage in weight of the component a is 5-15%, and that of the component b is 30-50%.

Advantageously, the b constituent is a zinc phosphate, for example the dihydric zinc phosphate, and preferably the zinc tetrahydric diphosphate Zn₃ (PO₄)2, 4H₂ O.

Among the preferred compositions, the mixtures containing 5-15% in weight of zinc 8-hydroxyquinolate and 30-60% in weight of zinc tetrahydric diphosphate.

The zinc 8-hydroxyquinolate, whose formula is Zn (C₉ H₆ O N)₂, 2H₂ O, is a known organometallic compound with a molecular weight of 389.4. It appears in the form of a yellowish green powder practically insoluble in water and in most organic solvents.

The derivatives of the zinc 8-hydroxyquinolate are used in human pharmaceuticals and veterinary products for their antiseptic properties.

The zinc 8-hydroxyquinolates, in particular those of divalent metals, are also used as fungicides in the field of agriculture.

However, the zinc 8-hydroxyquinolate is not known for its corrosion inhibiting properties and is not used in paintings and varnishes.

As regards the b component of the composition, it is selected among the phosphates, ferrites, borosilicates, phosphosilicates and oxides of some metals.

The chromates, phosphates, borates, and silicates are known as corrosion inhibitors.

The b component is preferably made of phosphates, and more particularly of zinc tetrahydric diphosphate Zn₃ (PO₄)₂ 4H₂ O. This last compound is used in the painting and varnish industry.

Surprisingly, the association of zinc 8-hydroxyquinolate, and corrosion inhibiting compounds here-above mentioned as b component, in particular metal phosphates, excites the anti-corrosive properties of each component.

Indeed, when pigmentary compositions are introduced according to the invention into painting formulations, an effect of synergy is highlighted leading to an anti-corrosive capacity,-higher or similar to that of zinc chromates in the considered formulations.

The painting formulations can be of any known type, as indicated previously.

The examples provided hereafter, on a non restrictive basis illustrate the efficiency against corrosion of paintings containing the pigmentary compositions according to the invention as well as their remarkable storage stability and their adherence, compared to anti-corrosive paintings containing zinc chromate.

In particular, formulations of anti-corrosive paintings of the same family have been carried out, one of them being based on a combination of zinc 8-hydroxyquinolate and zinc tetrahydric diphosphate, according to the invention, the others containing respectively zinc chromate and being based on other pigmentary associations available in the commerce and proposed as alternatives to the use of zinc chromates.

Among these pigmentary compositions of the commerce, those containing calcium ferrite, activated zinc phosphate, zinc and molybdenum basic phosphate, calcium borosilicate, zinc molybdeate, modified aluminum triphosphate, may be mentioned. The behaviours of these painting during some adhesive tests on metal supports have been compared.

The results obtained are shown in examples 1-5.

Example 6 concerns a reactive primary painting formulation with polyvinyl-butyral. It shows the efficiency in relation to the corrosion of a formulation according to the invention compared to a formulation containing zinc chromate.

The results obtained highlight, in the tested formulations, the superiority of the pigmentary compositions according to the invention, containing zinc 8-hydroxyquinolate.

EXAMPLE 1

A formulation of anticorrosive paint of the alkyde type (AFNOR family A class 4a) containing pigments according to the invention is prepared and compared to two test paints of a similar composition, respectively with a zinc chromate base (1) and with a calcium ferrite base (2).

The constituents of these three paint formation are shown in the hereafter table

    __________________________________________________________________________                          PARTS IN                                                                               PARTS IN  PARTS IN                                                     WEIGHT  WEIGH     WEIGHT                                  CONSTITUENT DESIGNATION                                                                             (INVENTION)                                                                            (TEST PIECE (1))                                                                         (TEST PIECE (2))                        __________________________________________________________________________     PIGMENTS                                                                       ZINC 8-HYDROXYQUINOLATE                                                                             1.50    --        --                                      TETRAHYDRIC          18.00   --        --                                      ZINC PHOSPHATE                                                                 ZINC CHROMATE        --      23.00     --                                      BASIC TYPE                                                                     CALCIUM FERRITE      --      --        24.00                                   TITANIA DIOXIDE (RUTILE)                                                                            7.00    5.00      7.00                                    YELLOW IRON OXIDE    6.50    --        7.50                                    VIOLET RED IRON OXIDE                                                                               1.50    2.00      --                                      MICRONISED TALCUM    5.00    5.00      5.00                                    NON ACICULAR ZINC    5.50    8.00      --                                      OXIDE                                                                          RESINS AND ADDITIVES                                                           LONG ALKYDE RESIN    38.00   40.00     38.00                                   in oil (70% in white                                                           spirit)                                                                        LEAD NAPHTHENATE SICCATIVE                                                                          1.00    1.20      1.20                                    COBALT NAPHTHENATE SICCATIVE                                                                        0.20    0.20      0.20                                    MANGANESE NAPHTHENATE                                                                               0.10    0.10      0.10                                    SICCATIVE                                                                      SOLVENTS AND DILUENTS                                                          WHITE SPIRIT         13.70   13.50     13.70                                   DIPENTENTE           2.00    2.00      2.00                                    TOTAL                100.00  100.00    100.00                                  __________________________________________________________________________

The physico-chemical characteristics of the anticorrosive paint formulations according to the invention and of the one with a zinc chromate base are mentioned in the hereafter table:

    __________________________________________________________________________     FORMULATION PRINCIPAL   ALKYDE TYPE FORMULATIONS                               PHYSICO-CHEMICAL CHARACTERISTICS                                                                       (AFNOR I CLASS 4a FAMILY)                              DESIGNATION             INVENTION TEST PIECE                                   __________________________________________________________________________     Extract in weight (%)   72.2      71.8                                         Dry extract in volume (%)                                                                              53.2      52.8                                         Pigments (% volume of the dry film)                                                                    33.2      29.9                                         Pigments (% in weight of paint)                                                                        45.0      43.0                                         Grinding fineness       7         7                                            Paint volume mass (g/cm3)                                                                              1.33      1.32                                         __________________________________________________________________________

The formulations are applied according to the invention and to the 2 mentioned test pieces in two layers on steel samples submitted to two types of surface preparation: a pickling at SA3 degree according to the Swedish standard n° SIS 05 59 00 1967 or a CST3 preparation according to the same standard (brushed rusty steel).

The total thickness of the dry film is 75-80 micrometers. The results of these tests, achieved with the paint formulation according to the invention, compared to those achieved with the two test formulations are summarized in the hereafter table.

    __________________________________________________________________________                               RESULTS        RESULTS                               COMPARATIVE RESULTS                                                                           PROTOCOLS OR                                                                              Invention compared to                                                                         Invention compared to                 REALIZED       REFERENCE  test piece (1) test piece (2)                        DESIGNATION    STANDARD   SA3 STEEL                                                                             CST3 STEEL                                                                             SA3 STEEL                                                                             CST3 STEEL                     __________________________________________________________________________     Accelerated salt                                                                              Protocol DPCM                                                                             (=)    ++      +      ++                             spray corrosion                                                                               1051/CERTSM87                                                   testing (1000 hours)                                                           Exposure to wet heat                                                                          G621-P10-4 ++             (=)                                   (3 weeks)      312/1                                                           Adherence on surface                                                                          AFNOR      (=)    (=)     -      -                              grid           NFT 30038                                                       Resistance test to                                                                            G621       (=)            +                                     flame propagation                                                                             P10-4-412                                                       (RPF)                                                                          Impact test to mass                                                                           AFNOR      (=)    (=)     (=)    (=)                            drop (before salt                                                                             NFT 30030                                                       spray)                                                                         Adhesive test under                                                                           Protocol DPCM                                                                             (=)    (=)     (=)    (=)                            high pressure water                                                                           CERTSM                                                          jet 180 bars                                                                   Flexibility test to                                                                           G621       (=)    (=)     (=)    (=)                            8 mm punch     P10-2-11                                                        Storage stability in                                                                          Periodic measu-                                                                           (=)    (= )    (=)                                   warehouse - 1 year                                                                            rements vis-                                                    (evolution of viscosi-                                                                        cosity                                                          ty)            KREBS-STORMER                                                   __________________________________________________________________________      KEY                                                                            - = behaviour slightly lower than the test piece behaviour                     (=) = similar to the test piece behaviour                                      + = slightly higher than the test piece behaviour                              ++ = much higher than the test piece behaviour                           

EXAMPLE 2

An epoxyvinyl-polyamide type formulation of anti-corrosive painting (AFNOR 1 class 6b 7a) containing pigments according to the invention is prepared and compared respectively to 2 test paintings containing zinc chromate (1) and an activated zinc of the commerce (2).

The components of these three painting formulations are shown in the table below.

    __________________________________________________________________________                    PARTS IN WEIGHT PARTS IN WEIGHT PARTS IN WEIGHT                 CONSTITUENT    (INVENTION)     (TEST PIECE (1))                                                                               (TEST PIECE (2))                DESIGNATION    ELEMENT A                                                                              ELEMENT B                                                                              ELEMENT A                                                                              ELEMENT B                                                                              ELEMENT A                                                                              ELEMENT                 __________________________________________________________________________                                                            B                       PIGMENTS                                                                       ZINC 8 HYDROXY-                                                                               1.6     --      --      --      --      --                      QUINOLATE                                                                      TETRAHYDRIC ZINC                                                                              18.0    --      --      --      --      --                      PHOSPHATE                                                                      ZINC CHROMATE  --      --      13.0    --      --      --                      INSOLUBLE TYPE                                                                 COMMERCE ACTIVATED                                                                            --      --      --      --      19.6    --                      ZINC PHOSPHATE                                                                 SYNTHETIC YELLOW                                                                              6.0     --      11.8    --      6.0     --                      IRON OXIDE                                                                     ANTIMONY OXIDE 4.0     --      6.0     --      4.0     --                      ORGANIC ORANGE 0.3     --      0.4     --      0.3     --                      MICRONISED TALCUM                                                                             4.0     --      --      --      4.0     --                      RESINS AND ADDITIVE                                                            TYPE 1 SOLID   16.0    --      17.0    --      16.0    --                      EPOXY RESIN                                                                    HYDROLYZED POLY-                                                                              4.0     --      4.3     --      4.0     --                      VINYL ACETYL-                                                                  CHLORIDE                                                                       COMPLEMENTARY  1.1     --      1.5     --      1.1     --                      RESINS AND TEN-                                                                SION ADDITIVE                                                                  POLYAMINOAMIDE --      71.0    --      71.0    --      71.0                    AT 70% ES                                                                      SOLVENTS AND                                                                   DILUENTS                                                                       KETONE SOLVENTS                                                                               27.0    --      27.5    --      27.0    --                      NAPHTA SOLVENT 18.0    --      18.3    --      18.0    --                      ETHOXYPROPANOL --      21.0    --      21.0    --      21.0                    BUTANOL - 1    --      8.0     --      8.0     --      8.0                     TOTAL          100     100     99.80   100     100     100                     Analysis                                                                            Element A A: 100 g        A: 100 g        A: 100 g                             Element B B: 16 g         B: 17 g         B: 16 g                         __________________________________________________________________________

The physico-chemical characteristics of these two anticorrosive paint formulations according to the invention and of the one with a zinc chromate base are mentioned in the hereafter table:

    __________________________________________________________________________     FORMULATION PRINCIPAL   EPOXYVINYL-POLYAMIDE TYPE                              PHYSICO-CHEMICAL CHARACTERISTICS                                                                       (AFNOR I FAMILY 6b 7a 1 CLASS)                         DESIGNATION             INVENTION TEST PIECE                                   __________________________________________________________________________     Dry extract in weight (%)                                                                              53.8      52.9                                         Dry extract in volume (%)                                                                              35.9      34.7                                         Pigments (% volume of the dry film)                                                                    30.3      22.5                                         Pigments (% paint weight)                                                                              29.2      26.7                                         Volume mass (A + B)     1.17      1.17                                         __________________________________________________________________________

The formulations are applied according to the invention and to the two mentioned test pieces are applied in two layers on steel samples subjected to a SA3 type surface preparation according to the Swedish standard SIS 05 59 00 1967

The average total thickness of the dry film is 50-60 micrometers. The results of the tests obtained with the paint formulation according to the invention compared to those obtained with the test formulations are summarized in the hereafter table.

    __________________________________________________________________________                               RESULTS                                                                               RESULTS                                       COMPARATIVE RESULTS                                                                           PROTOCOLS OR                                                                              Invention                                                                             Invention                                     REALIZED       REFERENCE  compared to                                                                           compared to                                   DESIGNATION    STANDARDS  test piece (1)                                                                        test piece (2)                                __________________________________________________________________________     Accelerated salt spray cor-                                                                   Protocol DPCM                                                                             +      +                                             rosion (testing 1200 hours)                                                                   5318 ET/SM                                                                     of 29.06.87                                                     Resistance to flame propaga-                                                                  G621-22.261                                                                               (=)    (=)                                           tion (RPF)                                                                     Adherence by tearing out                                                                      AFNOR NFT 30062                                                                           -      -                                             Control by adherence by                                                                       (angle 30 °)                                                                       (=)    (=)                                           double recess after exposure                                                   to salt spray (1200 h)                                                         Impact test by mass drop                                                                      AFNOR      (=)    (=)                                           (before salt spray)                                                                           NFT 30030                                                       Impact test by mass drop                                                                      AFNOR      (=)    (=)                                           (after salt spray)                                                                            NFT 30030                                                       Adherence by gridding                                                                         AFNOR NFT 30038                                                                           (=)    (=)                                           (before salt spray)                                                            Adherence by gridding after                                                                   AFNOR NFT 30038                                                                           (=)    +                                             exposure to salt spray                                                         Adhesive test under high                                                                      Protocol DPCM/                                                                            (=)    (=)                                           pressure water jet 180 bars                                                                   CERTSM                                                          (before salt spray)                                                            Adhesive test under high                                                                      Protocol DPCM                                                                             +      +                                             pressure water jet 180 bars                                                                   CERTSM                                                          (after salt spray)                                                             Storage stability in ware-                                                                    Periodic mea-                                                                             (= )   +                                             house - 1 year (evolution                                                                     surements                                                       of viscosity)  viscosity                                                                      KREBS-STORMER                                                   __________________________________________________________________________      KEY                                                                            - = behaviour slightly lower than the test piece behaviour                     (=) = similar to the test piece behaviour                                      + = slightly higher than the test piece behaviour                              ++ = much higher than the test piece behaviour                           

EXAMPLE 3

An anticorrosive paint formulation of the modified polyurethane type (AFNOR family I 7a 1-6a) containing pigmentes according to the invention is prepared and compared to 2 test paints with a similar composition, respectively with a zinc chromate base (1) and a zinc and molybdenum basic phosphate (2). The constituents of these 3 paint formulations are shown int he hereafter table

    __________________________________________________________________________     CONSTITUENT    PARTS IN WEIGHT PARTS IN WEIGHT PARTS IN WEIGHT                 DESIGNATION    (INVENTION)     (TEST PIECE (1))                                                                               (TEST PIECE (2))                PIGMENTS       ELEMENT A                                                                              ELEMENT B                                                                              ELEMENT A                                                                              ELEMENT B                                                                              ELEMENT A                                                                              ELEMENT                 __________________________________________________________________________                                                            B                       ZINC 8-HYDROXY-                                                                               1.9     --      --      --      --      --                      QUINOLATE                                                                      TETRAHYDRIC ZINC                                                                              7.7     --      --      --      --      --                      PHOSPHATE                                                                      ZINC CHROMATE  --      --      11.7                                            INSOLUBLE                                                                      ZINC AND       --      --      --      --      12.95   --                      MOLYBDENUM                                                                     BASIC PHOSPHATE                                                                ANTIMONY TRIOXIDE                                                                             10.0    --      10.1    --      10.00   --                      SYNTHETIC BLACK                                                                               4.0             0.5             4.00    --                      IRON OXIDE                                                                     MICRONISED TALCUM                                                                             3.0             3.7             3.00    --                      ORGANIC GREEN  0.3     --      1.5     --      0.3     --                      RESINS AND ADDITIVES                                                                          A       B       A       B       A       B                       SOLID POLYALCOHOL                                                                             7.0             7.0             7.00    --                      3% OH                                                                          HYDROLYZED POLY-                                                                              12.0            12.0            12.00   --                      VINYL ACETYL-                                                                  CHLORIDE                                                                       THIXOTROPING AGENT                                                                            0.5             0.5             0.50    --                      TRIARYLPHOSPHATE                                                                              2.4             2.4             2.40    --                      SOJA LECITHIN  0.1             0.1             0.10    --                      DESMODUR L67   --      50.0    --      50.0    --      50.00                   SOLVENTS AND   A       B       A       B       A       B                       DILUENTS                                                                       METHYLISOBUTYL-                                                                               40.5    --      34.0    --      40.50   --                      KETONE                                                                         XYLENE         9.5     --      16.0    --      9.50    --                      ANYDROUS TOLUENE                                                                              --      50.0    --      50.0    --      50.00                   TOTAL          98.9    100.0   100.0   100.0   102.25  100.0                   CORRESPONDING  ELEMENT A: 100 g                                                                               ELEMENT A: 100 g                                                                               ELEMENT A: 100 g                WEIGHT ANALYSIS                                                                               ELEMENT B: 3 g  ELEMENT B: 3.4 g                                                                               ELEMENT B: 3.5                  __________________________________________________________________________                                                    g                          

The physico-chemical characteristics of these two anticorrosive paint formulations according to the invention and of those with zinc chromate base are mentioned in the hereafter table:

    __________________________________________________________________________     FORMULATION PRINCIPAL   MODIFIED POLYRETHANE TYPE                              PHYSICO-CHEMICAL CHARACTERISTICS                                                                       (FAMILY AFNOR I CLASS 7a1-6a)                          DESIGNATION             INVENTION TEST PIECE                                   __________________________________________________________________________     Dry extract in weight (%)                                                                              50.56     50.00                                        Dry extract in volume (%)                                                                              about 30  about 29                                     Pigments (% dry film volume)                                                                           about 31  about 31                                     __________________________________________________________________________

The formulations according to the invention and the two mentioned test pieces are applied in two layers on steel samples subjected to a SA3 type surface preparation according to the Swedish standard SIS 05 59 00 - 1967.

The average total thickness of the dry film is 150 micrometers. The results of the tests obtained with the paint formulation according to the invention compared to those obtained with the test formulations are summarized in the following table.

    __________________________________________________________________________                               RESULTS                                                                               RESULTS                                       COMPARATIVE RESULTS                                                                           PROTOCOLS OR                                                                              Invention                                                                             Invention                                     REALIZED       REFERENCE  compared to                                                                           compared to                                   DESIGNATION    STANDARDS  test piece (1)                                                                        test piece (2)                                __________________________________________________________________________     Accelerated salt spray cor-                                                                   Protocol DPCM                                                                             +      (=)                                           rosion testing (1500 hours)                                                                   n° 1051/CERTSM/87                                        Exposure to wet heat                                                                          G621-P10-4 312/1                                                                          (=)    (=)                                           Adherence by grid before                                                                      AFNOR NFT 30038                                                                           (=)    (=)                                           exposure to salt spray                                                         Adherence by grid after                                                                       AFNOR NFT 30038                                                                           (=)    (=)                                           exposure to salt spray                                                         Impact test by mass drop                                                                      AFNOR NFT 30030                                                                           (=)    (=)                                           (before salt spray)                                                            Impact test by mass drop                                                                      AFNOR NFT 30030                                                                           (=)    (=)                                           (after salt spray)                                                             Tear out adhesive test                                                                        AFNOR NFT 30062                                                                           +      +                                             (before salt spray)                                                            Tear out adhesive test                                                                        AFNOR NFT 30062                                                                           ++     ++                                            (after salt spray)                                                             Adhesive test under high                                                                      Protocol DPCM/                                                                            ++     ++                                            pressure water jet 180 bars                                                                   CERTSM                                                          (before salt spray)                                                            Adhesive test under high                                                                      Protocol DPCM/                                                                            ++     ++                                            pressure water jet 180 bars                                                                   CERTSM                                                          (after salt spray)                                                             Storage stability in                                                                          Periodic mea-                                                                             +      (=)                                           warehouse - 1 year                                                                            surements                                                       (evolution of viscosity)                                                                      viscosity                                                                      KREBS STORMER                                                   Exposure test to sea spray                                                                    G621-P10-4.212                                                                            (=)    +                                             (1 year)       Panel of expo-                                                                 sure to sea                                                                    spray located                                                                  on the mole of                                                                 PIPAOY                                                                         (Toulon harbour)                                                __________________________________________________________________________      KEY                                                                            - = behaviour slightly lower than the test piece behaviour                     (=) = similar to the test piece behaviour                                      + = slightly higher than the test piece behaviour                              ++ = much higher than the test piece behaviour                           

EXAMPLE 4

A formulation of anticorrosive paint of the vinylic type (AFNOR family I, class 7a 1) containing pigments according to the invention has been prepared and it is compared to 5 test paints with a similar composition, respectively with a zinc chromate base (1), a commerce calcium borosilicate base (2), a zinc molybdate base (3), a zinc and molybdenum basic phosphate (4) and a commerce modified aluminum triphosphate base (5).

The constituents f the 6 paint formulations are shown int he hereafter table.

    __________________________________________________________________________                               PARTS IN                                                                             PARTS IN                                                                             PARTS IN                                                                             PARTS IN                                             PARTS IN                                                                               WEIGHT                                                                               WEIGHT                                                                               WEIGHT                                                                               WEIGHT                                                                               PARTS IN                     CONSTITUENT DESIGNATION                                                                          WEIGHT  TEST  TEST  TEST  TEST  WEIGHT                       TEST              INVENTION                                                                              PIECE (1)                                                                            PIECE (2)                                                                            PIECE (3)                                                                            PIECE (4)                                                                            PIECE                        __________________________________________________________________________                                                       (5)                          PIGMENTS                                                                       ZINC 8-HYDROXYQUINOLATE                                                                          1.9     --    --    --    --    --                           TETRAHYDRIC ZINC PHOS-                                                                           7.4     --    --    --    --    --                           PHATE                                                                          ZINC CHROMATE INSOLUBLE                                                                          --      9.0   --    --    --    --                           TYPE                                                                           CALCIUM BOROSILICATE                                                                             --      --    8.74  --    --    --                           ZINC MOLYBDENATE  --      --    --    17.0  --    --                           ZINC AND MOLYBDENUM                                                                              --      --    --    --    12.43 --                           BASIC PHOSPHATE                                                                MODIFIED ALUMINIUM TRI-                                                                          --      --    --    --    --    10.42                        PHOSPHATE                                                                      MICRONISED TALCUM 2.0     5.5   2.00  2.0   2.0   2.0                          CARBON BLACK      0.2     0.2   0.2   0.2   0.2   0.2                          SYNTHETIC YELLOW IRON                                                                            2.0     --    2.00  2.0   2.0   2.0                          OXIDE                                                                          RESINS AND ADDITIVES                                                           HYDROLIZED POLYVINYL                                                                             16.0    16.0  16.0  16.0  16.0  16.0                         ACETYLCHLORIDE                                                                 TRIARYLPHOSPHATE  1.5     1.5   1.5   1.5   1.5   1.5                          ANTISEDIMENTATION AGENT                                                                          0.5     0.5   0.5   0.5   0.5   0.5                          SOLVENTS AND DILUENTS                                                          METHYL ISOBUTYLKETONE                                                                            48.3    43.0  48.3  48.0  48.3  48.3                         TOLUENE           9.5     24.3  9.5   9.5   9.5   9.5                          XYLENE            9.5     --    9.5   9.5   9.5   9.5                          TOTAL             98.8    100.0 98.24 106.5 101.93                                                                               99.92                        __________________________________________________________________________

The physico-chemical characteristics of the anticorrosive paint formulations according to the invention and that with a zinc chromate base are mentioned in the hereafter table.

    __________________________________________________________________________     FORMULATION PRINCIPAL   VINYLIC TYPE FORMULATIONS                              PHYSICO-CHEMICAL CHARACTERISTICS                                                                       (AFNOR FAMILY I CLASS 7-a1)                            DESIGNATION             INVENTION                                                                               TEST PIECE                                    __________________________________________________________________________     Dry extract in weight (%)                                                                              31.9     32.6                                          Dry extract in volume (%)                                                                              18.3     18.0                                          Pigments (% dry film volume)                                                                           26.8     26.3                                          Pigments (% paint weight)                                                                              13.7     14.7                                          Paint volume mass (g/cm3)                                                                              0.98     1.01                                          Grinding fineness       7        7                                             __________________________________________________________________________

The formulations according to the invention and the 5 mentioned test pieces are applied in two layers on steel samples subjected to a SA3 type surface preparation according to Swedish standard SIS 05 59 00 - 1967.

The total average thickness of the dry film is 85 micrometers. The results of the tests obtained with the paint formulation according to the invention compared to those obtained with the tests formulations are summarized in the hereafter table.

    __________________________________________________________________________                               RESULTS                                                                              RESULTS                                                                              RESULTS                                                                              RESULTS                                                                              RESULTS                                                Invention                                                                            Invention                                                                            Invention                                                                            Invention                                                                            Invention                    COMPARATIVE RESULTS                                                                           PROTOCOLS OR                                                                              compared                                                                             compared                                                                             compared                                                                             compared                                                                             compared                     REALIZED       REFERENCE  to test                                                                              to test                                                                              to test                                                                              to test                                                                              to test                      DESIGNATION    STANDARDS  piece (1)                                                                            piece (2)                                                                            piece (3)                                                                            piece (4)                                                                            piece                        __________________________________________________________________________                                                       (5)                          Salt spray accelerated cor-                                                                   Protocol DPCM                                                                             ++    ++    +     ++    ++                           rosion test (1160 hours)                                                                      n° 1051/                                                                CERTSM/87                                                       Exposure to wet heat -                                                                        G621-P10-4 +     +     -     +     +                            6 weeks        312/1                                                           Adherence by grid before ex-                                                                  AFNOR      (=)   (=)   (=)   (=)   (=)                          posure to salt spray                                                                          NFT 30038                                                       Adherence by grid after ex-                                                                   AFNOR      (=)   ++    (=)   +     ++                           posure to salt spray 1160                                                                     NFT 30038                                                       hours                                                                          Impact test by mass drop,                                                                     AFNOR      (=)   (=)   (=)   (=)   (=)                          before salt spray                                                                             NFT 30030                                                       Impact test by mass drop,                                                                     AFNOR      (=)   (=)   (=)   (=)   (=)                          after salt spray                                                                              NFT 30030                                                       Tear out adhesive test                                                                        AFNOR      ++    (=)   +     +     ++                           (before salt spray)                                                                           NFT 30062                                                       Tear out adhesive test                                                                        AFNOR      ++    ++    +     ++    ++                           (after salt spray)                                                                            NFT 30062                                                       Adhesive test under high                                                                      Protocol DPCM                                                                             -     (=)   (=)   -     +                            pressure water jet 180 bars                                                                   CERTSM                                                          (before salt spray)                                                            Adhesive test under high                                                                      Protocol DPCM                                                                             +     ++    (=)   ++    ++                           pressure water jet 180 bars                                                                   CERTSM                                                          (after salt spray)                                                             Storage stability in                                                                          Periodic mea-                                                                             -     -     (=)   -     -                            warehouse - 1 year                                                                            surements                                                       (evolution of viscosity)                                                                      viscosity                                                                      KREBS-STORMER                                                   Sea spray exposure                                                                            G621-P10-212                                                                              +     -     ++    ++    +                            test (1 year)  Panel of ex-                                                                   posure to sea                                                                  spray located                                                                  on the mole                                                                    of PIPAOY                                                                      Toulon har-                                                                    bour                                                            __________________________________________________________________________      KEY                                                                            - = behaviour slightly lower than the test piece behaviour                     (=) = similar to the test piece behaviour                                      + =  slightly higher than the test piece behaviour                             ++ = much higher than the test piece behaviour                           

EXAMPLE 5

A chlorinated rubber type paint formulation (AFNOR family 1 class 8a) containing pigments according to the invention is prepared and compared to 5 test paints with a similar composition, respectively with a zinc chromate base (1), a calcium borosilicate base (2), a zinc molybdate base (3), a modified aluminum triphosphate base (4), and a zinc and molybdenum basic phosphate base (5).

The constituents of the 6 paint formulations are shown int he hereafter table.

    __________________________________________________________________________                               PARTS IN                                                                             PARTS IN                                                                             PARTS IN                                                                             PARTS IN                                             PARTS IN                                                                               WEIGHT                                                                               WEIGHT                                                                               WEIGHT                                                                               WEIGHT                                                                               PARTS IN                     CONSTITUENT DESIGNATION                                                                          WEIGHT  TEST  TEST  TEST  TEST  WEIGHT                       TEST              INVENTION                                                                              PIECE (1)                                                                            PIECE (2)                                                                            PIECE (3)                                                                            PIECE (4)                                                                            PIECE                        __________________________________________________________________________                                                       (5)                          PIGMENTS                                                                       ZINC 8-HYDROXYQUINOLATE                                                                          2.95    --    --    --    --    --                           TETRAHYDRIC ZINC PHOS-                                                                           11.75   --    --    --    --    --                           PHATE                                                                          ZINC CHROMATE INSOLUBLE                                                                          --      19.3  --    --    --    --                           TYPE                                                                           CALCIUM BOROSILICATE                                                                             --      --    13.94 --    --    --                           ZINC MOLYBDENATE  --      --    --    27.13 --    --                           MODIFIED ALUMINIUM                                                                               --      --    --    --    16.62 --                           TRIPHOSPHATE                                                                   ZINC AND MOLYBDENUM                                                                              --      --    --    --    --    19.84                        BASIC PHOSPHATE                                                                MICRONISED TALCUM 2.5     2.5   2.5   2.5   2.5   2.5                          BLACK CARBON      0.7     0.7   0.7   0.7   0.7   0.7                          SYNTHETIC RED IRON OXIDE                                                                         5.8     5.8   5.8   5.8   5.8   5.8                          RESINS AND ADDITIVES                                                           10 CPS CHLORINATED                                                                               13.1    13.1  13.1  13.1  13.1  13.1                         RUBBER RESIN                                                                   CHLORINATED PARAFFIN AT                                                                          5.8     5.8   5.8   5.8   5.8   5.8                          42% OF CHLORINE                                                                CHLORINATED PARAFFIN AT                                                                          8.0     8.0   8.0   8.0   8.0   8.0                          70% OF CHLORINE                                                                THIXOTROPING AGENT                                                                               1.4     1.4   1.4   1.4   1.4   1.4                          SOLVENTS AND DILUENTS                                                          ETHOXYPROPANOL ACETATE                                                                           8.5     --    8.5   8.5   8.5   8.5                          ETHYLENE GLYCOL ACETATE                                                                          --      8.5   --    --    --    --                           XYLENE            34.9    34.9  34.9  34.9  34.9  34.9                         TOTAL             95.4    100.0 94.64 107.83                                                                               97.32 100.54                       __________________________________________________________________________

The physico-chemical characteristics of the anticorrosive paint formulations according to the invention and to that with a zinc chromate base are mentioned in the hereafter table.

    __________________________________________________________________________     FORMULATION PRINCIPAL   CHLORINATED RUBBER TYPE                                PHYSICO-CHEMICAL CHARACTERISTICS                                                                       (AFNOR FAMILY I CLASS 8a)                              DESIGNATION             INVENTION                                                                               TEST PIECE                                    __________________________________________________________________________     Dry extract in weight (%)                                                                              54.5     56.6                                          Dry extract in volume (%)                                                                              35.7     35.8                                          Pigments (% dry film volume)                                                                           28.7     28.6                                          Pigments (% paint weight)                                                                              24.8     28.3                                          Paint volume mass (g/cm3)                                                                              1.24     1.3                                           Grinding fineness       6        6                                             __________________________________________________________________________

The two formulations according to the invention and the 5 mentioned test pieces are applied in three layers on steel samples subjected to a SA3 type surface preparation according to the Swedish standard SIS 05 59 00 - 1967.

The total average thickness of the dry film is 240 micrometers. The results of the tests obtained with the paint formulation according to the invention compared to those obtained with the 5 test formulations are summarized in the hereafter table.

    __________________________________________________________________________                               RESULTS                                                                              RESULTS                                                                              RESULTS                                                                              RESULTS                                                                              RESULTS                                                Invention                                                                            Invention                                                                            Invention                                                                            Invention                                                                            Invention                    COMPARATIVE RESULTS                                                                           PROTOCOLS OR                                                                              compared                                                                             compared                                                                             compared                                                                             compared                                                                             compared                     REALIZED       REFERENCE  to test                                                                              to test                                                                              to test                                                                              to test                                                                              to test                      DESIGNATION    STANDARDS  piece (1)                                                                            piece (2)                                                                            piece (3)                                                                            piece (4)                                                                            piece                        __________________________________________________________________________                                                       (5)                          Salt spray accelera-                                                                          Protocol DPCM                                                                             +     +     ++    ++    ++                           ted corrosion test                                                                            n° 1051/                                                 (1160 hours)   CERTSM/87                                                       Exposure to wet heat -                                                                        G621-P10-4 ++    ++    +     ++    +                            6 weeks        312/1                                                           Adherence by grid                                                                             AFNOR      (=)   (=)   (=)   (=)   (=)                          before exposure to                                                                            NFT 30038                                                       salt spray                                                                     Adherence by grid                                                                             AFNOR      ++    +     +     ++    ++                           after exposure to salt                                                                        NFT 30038                                                       spray                                                                          Impact test by mass                                                                           AFNOR      (=)   (=)   (=)   (=)   (=)                          drop (before salt                                                                             NFT 30030                                                       spray)                                                                         Impact test by mass                                                                           AFNOR      (=)   (=)   +     (=)   (=)                          drop (after salt                                                                              NFT 30030                                                       spray)                                                                         Tear out adhesive test                                                                        AFNOR      --    -     --    -     -                            (before salt spray)                                                                           NFT 30062                                                       Tear out adhesive test                                                                        AFNOR      -     ++    ++    ++    -                            (after salt spray)                                                                            NFT 30062                                                       Adhesive test under                                                                           Protocol DPCM                                                                             ++    ++    +     +     ++                           high pressure water                                                                           CERTSM                                                          jet - 180 bars (before                                                         salt spray)                                                                    Adhesive test under                                                                           Protocol DPCM                                                                             ++    +     ++    ++    +                            high pressure water                                                                           CERTSM                                                          jet 180 bars (after                                                            salt spray)                                                                    Storage stability in                                                                          Periodic mea-                                                                             (=)   +     -     (=)   +                            warehouse - 1 year                                                                            surements of                                                    (evolution of visco-                                                                          viscosity                                                       sity)          KREBS-STORMER                                                   Exposure test to sea                                                                          Sea spray  (=)   (=)   ++    ++    ++                           spray (1 year) exposure panel                                                                 located at                                                                     PIPAOY mole                                                                    (Toulon har-                                                                   bour)                                                           __________________________________________________________________________      KEY                                                                            - = behaviour slightly lower than the test piece behaviour                     (=) = similar to the test piece behaviour                                      + = slightly higher than the test piece behaviour                              ++ = much higher than the test piece behaviour                           

EXAMPLE 6

A primary paint formulation reactive to polyvinylic butyral containing pigments according to the invention is prepared and compared to a zinc chromate test paint. The constituents of the two paint formulations are shown in the hereafter table.

    __________________________________________________________________________     CONSTITUENT      PARTS IN WEIGHT PARTS IN WEIGHT                               DESIGNATION      (INVENTION)     (TEST PIECE)                                  __________________________________________________________________________     PIGMENTS AND FILLING                                                                            ELEMENT A                                                                              ELEMENT B                                                                              ELEMENT A                                                                              ELEMENT B                             MATERIAL                                                                       ZINC 8 HYDROXY-  1.00    --      --      --                                    QUINOLATE                                                                      TETRAHYDRIC ZINC 6.70    --      --      --                                    PHOSPHATE                                                                      ZINC CHROMATE    --      --      11.00   --                                    INSOLUBLE TYPE                                                                 BLUISH PHTHALOCYANINE                                                                           0.20    --      0.10    --                                    GREEN                                                                          RUTILE DIOXIDE   1.0     --      1.00    --                                    MICRONISED TALCUM                                                                               --      --      3.00    --                                    RESINS SOFTENERS A       B       A       B                                     AND ADDITIVES                                                                  POLY-VINYLIC     11.70   --      9.00    --                                    BUTYRAL                                                                        BENTONE 27       0.20    --      0.80    --                                    "SPECIAL" TEXAPHOR                                                                              1.80    --      0.90    --                                    (72% dry extract)                                                              PHOSPHORIC ACID  --      22.40   --      22.40                                 (85%)                                                                          SOLVENTS AND     A       B       A       B                                     DILUENTS                                                                       NORMAL BUTANOL   66.30   72.20   68.00   72.20                                 95% BUTYL ALCOHOL                                                                               9.30    5.40    5.20    5.40                                  DEMINERALIZED WATER                                                                             1.80    --      1.00    --                                    TOTAL            100.00  100.00  100.00  100.00                                CORRESPONDING ANALYSIS                                                                          ELEMENT A: 100 g                                                                               ELEMENT A: 100 g                              IN WEIGHT        ELEMENT B: 25.1 g                                                                              ELEMENT B: 19.3 g                             __________________________________________________________________________

These two formulations are applied on 500×500× mm steel sheets, pickled by projection of abrasive (sanding) to SA3 degree according to Swedish standard SIS 055900-1967.

The dry film average thickness is 10-15 micrometers. The exposure has been made on a panel tilted at 45 degrees in sea atmosphere, in winter (January-February 1990) during 5 weeks.

The results of the corrosion resistance tests are the following:

Formulation according to the invention: practically no corrosion is observed (it is lower than 5% of the surface)

Test formulation with zinc chromate: significant corrosion on approximately 50% of the surface from the first week of exposure. 

I claim:
 1. Anti-corrosive pigmentary composition for coating, characterized in that it contains zinc 8-hydroxyquinolate and at least one pigment.
 2. Composition according to claim 1 characterized in that it contains at least one of the following pigments: zinc phosphate, iron phosphate, chromium phosphate, manganese phosphate, aluminum phosphate, aluminum oxide, calcium ferrite, zinc ferrite, magnesium ferrite, barium ferrite, iron ferrite, calcium borosilicate, barium borosilicate, calcium phosphosilicate, and barium phosphosilicate.
 3. Pigmentary composition according to claim 2, characterized in that it comprises a pigment pulverulent mixture including, in combination, the percentages being expressed in comparison to the total weight of the pigment mixture:a) 0.5-99.5% by weight of zinc 8-hydroxyquinolate, b) 0.5-99.5% by weight of at least one of the following pigments: zinc phosphate, iron phosphate, chromium phosphate, manganese phosphate, aluminum phosphate, aluminum oxide, calcium ferrite, zinc ferrite, magnesium ferrite, barium ferrite, iron ferrite, calcium borosilicate, barium borosilicate, calcium phosphosilicate, and barium phosphosilicate.
 4. Composition according to claim 3, characterized in that it contains 5-15% by weight of component a and 30-60% by weight of component b.
 5. Composition according to claim 4, characterized in that component b is a zinc phosphate.
 6. Composition according to claim 5, characterized in that the component b is zinc tetrahydric diphosphate, Zn₃ (PO₄), 4H₂ O.
 7. Composition according to claim 6, characterized in that it contains 5-15% by weight of zinc 8-hydroxyquinolate and 30-60% by weight of zinc tetrahydric diphosphate.
 8. Paint characterized in that it contains an anti-corrosive pigmentary composition according to claim
 1. 9. Paint according to claim 8, characterized in that it contains binders in aqueous dispersion or in solution in an organic, solvent.
 10. Paint according to claim 9, characterized in that the binders are selected among acrylic polymeric compounds, vinyl, alkyde resins, epoxy resins, polyurethanes, chlorinated rubber, and polyvinyl butyral. 